High volume manufacturing equipment such as a conversion press described in U.S. Pat. No. 4,026,276, for converting basic can ends into easy open ends requires considerable auxiliary apparatus, tooling and gaging devices to facilitate the speed and automation required for high product quality and minimal scrap generation. As a result, the introduction and design of auxiliary apparatus is often constrained by the availability of space for the placement of the apparatus.
One of the problems associated with such press operations is the need to feed soft metal or plastic to the press for use in the construction of opening tabs particularly when such tabs are of a composite nature. The high production rates require that the strip stock be rapidly fed, but at the same time the advancement must be in discrete increments rather than in a continuous manner.
Incremental strip feeders are known which employ pinch rolls with the drive roll disposed beneath an overhead floating roll and wherein the strip is threaded between the rolls for incremental advancement. These strip feeders tend to compress and deform soft stock. Incremental strip feeders are also known in which a depending finger is reciprocated to push the strip in incremental advancement. At the end of the forward stroke, the finger is mechanically raised thereby releasing the strip and allowing the finger to be returned for the next advancement. This structure lacks the requisite precision for the manufacture of composite open tabs.
Accordingly it is an objective of this invention to provide a reliable strip feed which can incrementally advance a soft strip or foil without defacing or otherwise damaging the surface thereof.
It is further an objective of this invention to provide a strip feed unit which can precisely advance the strip by minimizing the slack or lost motion of the strip in each incremental advance.
Finally, it is an objective of this invention to provide a compact strip feed unit which is economical to manufacture and service and which may be readily incorporated onto apparatus when the availability of space is limited.
The inventor is not aware of any art which is material to the examination of the application.